On this day (26 February) in 1946, Egyptian-American chemist Ahmed Zewail was born. Zewail pioneered femtochemistry, the use of laser pulses to see the movement of individual atoms during chemical reactions. This graphic gives an overview of the ultrafast laser spectroscopy that makes this possible.
What do the various different arrows used by chemists all mean? That’s the question this short summary graphic aims to answer, by highlighting the most common arrows encountered in chemistry lessons and textbooks and giving a brief explanation of their use with examples.
When you think of chemical reactions, you might think of them as irreversible, permanently changing one substance into another. While this is true in some cases, some chemical reactions are reversible, and we can take the products of the reaction and turn them back into the reactants. These reversible reactions can, under certain conditions, reach what we call ‘equilibrium’. Equilibrium can be a tricky concept to understand, but this graphic tries to make it a little clearer.
How different factors can affect how quickly a reaction happens is a common topic in the chemistry curriculum. This graphic serves as a convenient summary for teachers and students alike of what these different factors are, and how and why they affect the rate of a reaction. However, it’s not only of interest to those teaching or learning about chemistry; as we’ll see, knowledge of these factors can have some everyday applications too!
Glassware in the laboratory comes in a range of different shapes and sizes, and is used for a number of purposes. Don’t know your round-bottomed flask from your Florence flask, or your pipettes from your burettes? This graphic has you covered. Below there’s also a little detail on the usage of each.
Today, 23rd October is Mole Day – which might put you in mind of small, furry, burrowing animals. However, they don’t even seem to have a commemorative day of any kind; we’re actually talking about the mole in chemistry, a concept that makes it easier to talk about the amounts of substances involved in chemical reactions. This is a fundamental concept and one that all chemists utilise.
